PRIMUS is the band that composed and performed the South Park Theme, and the frontman of the group, Les CLaypool sings the song. Les Claypool is somewhat a South Park character as well, with a few appearances on the show. He appears in the opening, singing the theme song in most of the episodes of the show from seasons 1-4 ("Cartman Gets An Anal Probe" to "4th Grade") He also appears on the intro when the show airs in syndication.